diff options
Diffstat (limited to 'arch/x86/boot')
| -rw-r--r-- | arch/x86/boot/Makefile | 10 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/Makefile | 20 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_32.S | 28 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 8 | ||||
| -rw-r--r-- | arch/x86/boot/cpuflags.h | 2 | ||||
| -rw-r--r-- | arch/x86/boot/mkcpustr.c | 2 | ||||
| -rw-r--r-- | arch/x86/boot/tools/build.c | 1 |
7 files changed, 65 insertions, 6 deletions
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index bbe1a62ef..b1ef9e489 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -9,7 +9,15 @@ # Changed by many, many contributors over the years. # -KASAN_SANITIZE := n +KASAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y + +# Kernel does not boot with kcov instrumentation here. +# One of the problems observed was insertion of __sanitizer_cov_trace_pc() +# callback into middle of per-cpu data enabling code. Thus the callback observed +# inconsistent state and crashed. We are interested mostly in syscall coverage, +# so boot code is not interesting anyway. +KCOV_INSTRUMENT := n # If you want to preset the SVGA mode, uncomment the next line and # set SVGA_MODE to whatever number you want. diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index f9ce75d80..8774cb230 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -16,13 +16,17 @@ # (see scripts/Makefile.lib size_append) # compressed vmlinux.bin.all + u32 size of vmlinux.bin.all -KASAN_SANITIZE := n +KASAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y + +# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. +KCOV_INSTRUMENT := n targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 KBUILD_CFLAGS := -m$(BITS) -D__KERNEL__ $(LINUX_INCLUDE) -O2 -KBUILD_CFLAGS += -fno-strict-aliasing -fPIC +KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC) KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING cflags-$(CONFIG_X86_32) := -march=i386 cflags-$(CONFIG_X86_64) := -mcmodel=small @@ -36,6 +40,18 @@ GCOV_PROFILE := n UBSAN_SANITIZE :=n LDFLAGS := -m elf_$(UTS_MACHINE) +ifeq ($(CONFIG_RELOCATABLE),y) +# If kernel is relocatable, build compressed kernel as PIE. +ifeq ($(CONFIG_X86_32),y) +LDFLAGS += $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker) +else +# To build 64-bit compressed kernel as PIE, we disable relocation +# overflow check to avoid relocation overflow error with a new linker +# command-line option, -z noreloc-overflow. +LDFLAGS += $(shell $(LD) --help 2>&1 | grep -q "\-z noreloc-overflow" \ + && echo "-z noreloc-overflow -pie --no-dynamic-linker") +endif +endif LDFLAGS_vmlinux := -T hostprogs-y := mkpiggy diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 8ef964ddc..0256064da 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -31,6 +31,34 @@ #include <asm/asm-offsets.h> #include <asm/bootparam.h> +/* + * The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X + * relocation to get the symbol address in PIC. When the compressed x86 + * kernel isn't built as PIC, the linker optimizes R_386_GOT32X + * relocations to their fixed symbol addresses. However, when the + * compressed x86 kernel is loaded at a different address, it leads + * to the following load failure: + * + * Failed to allocate space for phdrs + * + * during the decompression stage. + * + * If the compressed x86 kernel is relocatable at run-time, it should be + * compiled with -fPIE, instead of -fPIC, if possible and should be built as + * Position Independent Executable (PIE) so that linker won't optimize + * R_386_GOT32X relocation to its fixed symbol address. Older + * linkers generate R_386_32 relocations against locally defined symbols, + * _bss, _ebss, _got and _egot, in PIE. It isn't wrong, just less + * optimal than R_386_RELATIVE. But the x86 kernel fails to properly handle + * R_386_32 relocations when relocating the kernel. To generate + * R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as + * hidden: + */ + .hidden _bss + .hidden _ebss + .hidden _got + .hidden _egot + __HEAD ENTRY(startup_32) #ifdef CONFIG_EFI_STUB diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index b0c0d16ef..86558a199 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -33,6 +33,14 @@ #include <asm/asm-offsets.h> #include <asm/bootparam.h> +/* + * Locally defined symbols should be marked hidden: + */ + .hidden _bss + .hidden _ebss + .hidden _got + .hidden _egot + __HEAD .code32 ENTRY(startup_32) diff --git a/arch/x86/boot/cpuflags.h b/arch/x86/boot/cpuflags.h index ea97697e5..4cb404fd4 100644 --- a/arch/x86/boot/cpuflags.h +++ b/arch/x86/boot/cpuflags.h @@ -1,7 +1,7 @@ #ifndef BOOT_CPUFLAGS_H #define BOOT_CPUFLAGS_H -#include <asm/cpufeature.h> +#include <asm/cpufeatures.h> #include <asm/processor-flags.h> struct cpu_features { diff --git a/arch/x86/boot/mkcpustr.c b/arch/x86/boot/mkcpustr.c index 637097e66..f72498dc9 100644 --- a/arch/x86/boot/mkcpustr.c +++ b/arch/x86/boot/mkcpustr.c @@ -17,7 +17,7 @@ #include "../include/asm/required-features.h" #include "../include/asm/disabled-features.h" -#include "../include/asm/cpufeature.h" +#include "../include/asm/cpufeatures.h" #include "../kernel/cpu/capflags.c" int main(void) diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c index a7661c430..0702d2531 100644 --- a/arch/x86/boot/tools/build.c +++ b/arch/x86/boot/tools/build.c @@ -49,7 +49,6 @@ typedef unsigned int u32; /* This must be large enough to hold the entire setup */ u8 buf[SETUP_SECT_MAX*512]; -int is_big_kernel; #define PECOFF_RELOC_RESERVE 0x20 |